Process for preparing lubricating oil addends



Patented July 18, 1950 PRooEs s ort PREPARING VLUBRICATING;

' OIL ADDENDS.

Franklin M., Watkins,.Flossmoor, Ill., assignor to Sinclair. Refining Company, New York, N. Y., a.corporation.0flMaine No Drawing: Application; J 111166,; 19.46, Serial No. 674,923..

2 Claims. (Cl. zoos-139 i My: invention; relates. toa, method for remov ing; oxygen compounds from turpentine; by which term I mean to: embrace not only turpentine itself, but also turpentine fractions, in cluding turpentine oil andr the material sold under the'name Pinene 111,, whichis a fractionated turpentine reported as containing about.9.2 alpha pinene, 4-5% camphene, and 3-4 dipentone and other terpenes.

Copending application, Serial No. 494:,687 of- Robert L. May; filed July 14; 1943, Patent No. 2,486,188, issued October 25, 1949 describes a phosphorusand sulfur-containing. addend for mineral. and lubricating. oils,. which. is,- obtained by reaction of a phosphorus sulfide, with. turpentine, while May applications, Serial Nos. 545,193

and 545,195, both filed July 15, 1944', now Patents Nos. 2,409,877 and 2,409,878, bothissued- In the; practice of my process, I generally heatthe turpentine in the pr'esence'of' the sodium to reflux temperature andretain it at such tern.- perature' for about 5 hours. Thereafter, I may simply distill the mixture, taking-{as product of the process, a, fraction boiling within a. predetermined boilingrange or; alternatively, I may take, as the product, the clear liquid obtainable by filtration. and decantation of the residue"follow inga distillation carriedout at a temperature: up to the boiling range of the product.

The following; examples submitted'in' illustra-= tiorr ofjmyinvention are not to be construed as'inany way restrictive of the scope thereofz' Example 1 In a blank test, ,a sample of Pinene 111, 544 grams, (Fl moles) was. heated; on; a sand bathina three liter three-necked' flask equipped with a mechanical stirrer. After the temperature reached, 25091 thesource of heatwas removedand. 2,221 grams, 1 mole,.of phosphorus pentasul'fide Was added insmall increments 'over' a 90' minute period, the temperature ofthe exotherit has recently been discovered, derives from oxygen impurities naturally' present or formed in the turpentine used inthe preparation of' the phosphorus sulfide-turpentine reaction product.

The oxygen impurities apparently react with the phosphorus sulfide, forming sulfur derivatives which are directly responsible for the odor. In the case of the addend of the first of the May applications, above identified, the odor is usually not noticeable in the addend itself but develops following addition of the addend to the lubricating oil.

According to the present invention, I remove or inactivate a substantial portion of these ox gen compounds before the turpentine is reacted with the phosphorus sulfide and I thereby materially improve the odor of compounded oils containing the addends. I accomplish this by a process which comprises heating the turpentine over metallic sodium.

I am not certain as to the mechanism of the reaction involved in my process but it appears that the sodium causes the polymerization of some of the oxygen impurities and that sodium derivatives of other of the oxygen impurities are formed which do not react with phosphorus sulfides.

mic reaction bein thereby: maintained at; "about 275 F. After the addition of the last increment of the. phosphorus. pentasulfide, the reaction wasgcontinued 01512 hours at 275 following which 176 grams, 1 mole, of p-cyclohexylphenpl was added. Aiter further, reaction for 10 hours at 275," thev mixture Was blended, with 1022 grams of a low viscosity mid-continent oil. 2 parts by weight of the resulting oil concentrate; after filtration, was mixed with 97% parts by weight of a mid-continent SAE 20 motor oil. This blend had an offensive onion-like odor suggestive of mercaptans.

Example 2 A second sample of the Pinene 111 was distilled and 544 grams of the overhead (boiling at 156-157 C.) was reacted with phosphorus pentasulfide and p-cyclohexylphenol, the procedure being the same as that described in Example 1 except that an atmosphere of nitrogen was maintained in the reaction flask. The odor of the final blend was equivalent to that of the final blend of Example 1.

Example 3 was nearly odorless. A sample of ordinary turpentine, treated in a similar manner, gave a blend, which while more odoriferous than the blend prepared with the sodium-treated Pinene 111, was much superior in the respect of odor to a blend containing the turpentine phosphorussulfide reaction product turpentine;

Example 4 A second portion of the fraction obtained in the distillation of Example 3 was employed acprepared with untreated produce compounds which have an objectionable odorand which are thermally unstable.

cording to Example 1. The final blend was relatively odorless as compared to the final blend of I, 1

Example 1.

Apart from the fact that it improves the odor of the blends, my process is advantageous in that the addend is rendered more thermally stable; Thus, when the phosphorus sulfide-turpentine reaction product, prepared with turpentine which has been treated according to my process, is heated under reflux at 350 F. for as longas 16 hours, no decomposition, as would be indicated by the formation of a precipitate, occurs. On the other "hand, when thereaction product is prepared, as heretofore, with turpentine from which oxygen impurities have not been removed, a precipitate is formed in two hours and the precipitate progressively increases in quantity on further heating.

Where the turpentine to be processed according to my invention has a high peroxide content, it is advantageous to subject it to a pretreatment withcaustic soda or other alkali. In the pretreatment as effected with caustic soda, I generally use about 1 part by weight of 40% aqueous caustic for each 20 parts of the turpentine, refluxing the mixture for a period of some 8-10 hours. Contrary to what might be expected, the alkali treatment alone will not remove oxygen compounds responsible for the objectionable odor in the blends.

Following the purification treatment of the in- 2. In aprocess for preparing a lubricating oil addend whichinvolves subjecting a turpentine which initially includes oxygen-containing impurities to reaction with phosphorus pentasulfide at 'atemperature approximating 275 F.

whereby there is produced an oil-soluble phosphorus-Land sulfur-containing reaction product useful as a lubricating oil addend, the improvement comprising subjecting, the turpentine including theoxygen-containingimpurities prior to reaction of 'the turpentine with phosphorus pentasulfide, to heating at refluxing temperature in the presence of metallic sodium and then distilling the reaction product, whereby the turvention, an oxidation inhibitor, such as hydropentine is rendered substantially free of oxygencontaining impurities that are reactive with phosphorus pentasulfide to produce compounds which have an objectionable odor and which are thermally unstable. y

Y I FRANKLIN M. WATKINS.

REFERENCES CITED The following references are of record in the file. of this patent;

1 UNITED STATES PATENTS I OTHER REFERENCES Henrich Chem. Abs. vol. 15, 3757 (1929).

Kuwata Jour. of the Faculty of Eng. Tokyo Imperial University, Tokyo, Japan, vol. XVIII, No. 5, (1929). 

2. IN A PROCESS FOR PREPARING A LUBRICATING OIL ADDEND WHICH INVOLVES SUBJECTING A TURPENTINE WHICH INITIALLY INCLUDES OXYGEN-CONTAINING IMPURITIES TO RETURN WITH PHOSPHORUS PENTASULFIDE AT A TEMPERATURE APPROXIMATING 275*F. WHEREBY THERE IS PRODUCED AN OIL-SOLUBLE PHOSPHOROUS- AND SULFUR-CONTAINING REACTION PRODUCT USEFUL AS A LUBRICATING OIL ADDEND, THE IMPROVEMENT COMPRISING SUBJECTING THE TURPENTINE INCLUDING THE OXYGEN-CONTAINING IMPURITIES PRIOR TO REACTION OF THE TURPENTINE WITH PHOSPHOROUS PENTASULFIDE, TO HEATING AT REFLUXING TEMPERATURE IN THE PRESENCE OF METALLIC SODIUM AND THEN DISTILLING THE REACTION PRODUCT, WHEREBY THE TURPENTINE IS RENDERED SUBSTANTIALLY FREE OF OXYGENCONTAINING IMPURITIES THAT ARE REACTIVE WITH PHOSPHOROUS PENTASULFIDE TO PRODUCE COMPOUNDS WHICH HAVE AN OBJECTIONABLE ODOR AND WHICH ARE THERMALLY UNSTABLE. 